Win.Trojan.Vbkrypt-9795 — RTF / .DOC malware analysis

Static analysis result for SHA-256 5e4bd58473759ad3…

MALICIOUS

RTF / .DOC

81.3 KB Authoring application: Msftedit 5.41.15.1515
MD5: 056f64ce2d8e65f1165ed94bd9f4bf09 SHA-1: f3ada86829d5cf332d81236b7a86f4fb6aa685be SHA-256: 5e4bd58473759ad38aed0d7cc5b5c29b8f5306967affe4fc4842cc7785687c59
260 Risk Score

Malware Insights

Win.Trojan.Vbkrypt-9795 · confidence 95%

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1027 Obfuscated Files or Information

The RTF file contains embedded OLE objects, including a PE executable identified by ClamAV as Win.Trojan.Vbkrypt-9795. The presence of RTF_MZ_HEX and RTF_OBJCLASS_PACKAGE heuristics indicates that a malicious executable is embedded within the document. The document body suggests a pretext of legal documents, which is a common lure for malicious attachments.

Heuristics 6

  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
  • ClamAV: Win.Trojan.Vbkrypt-9795 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Vbkrypt-9795
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Package object class high RTF_OBJCLASS_PACKAGE
    OLE Package object — can wrap arbitrary files
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000cf.bin
4a1f38027de09064737e8a0e659b6d230b995380e967dfc2f919c646ad7ef6f3
rtf-objdata-decoded RTF \objdata at offset 0xCF 36651 bytes
Detection
ClamAV: Win.Trojan.Vbkrypt-9795
Obfuscation or payload: unlikely